<!DOCTYPE html>
<html>
<head>
   <meta charset="utf-8"> 
   <title>在线尝试 Bootstrap 实</title>
   <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css">  
   <script src="https://cdn.bootcss.com/jquery/2.1.1/jquery.min.js"></script>
   <script src="https://cdn.bootcss.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>
<body>

      <p>
	<button type="button" class="btn btn-default">
		<span class="glyphicon glyphicon-sort-by-attributes"></span>
	</button>
	<button type="button" class="btn btn-default">
		<span class="glyphicon glyphicon-sort-by-attributes-alt"></span>
	</button>
	<button type="button" class="btn btn-default">
		<span class="glyphicon glyphicon-sort-by-order"></span>
	</button>
	<button type="button" class="btn btn-default">
		<span class="glyphicon glyphicon-sort-by-order-alt"></span>
	</button>
</p>

<button type="button" class="btn btn-default btn-lg">
	<span class="glyphicon glyphicon-user"></span> 登  录
</button>
<button type="button" class="btn btn-default btn-sm">
	<span class="glyphicon glyphicon-user"></span> User
</button>
<button type="button" class="btn btn-default btn-xs">
	<span class="glyphicon glyphicon-user"></span> User
</button>

</body>
</html>